The manufacture of containers by blow molding them out of parisons made of a thermoplastic material, for example out of parisons made of PET (polyethylene terephthalate), wherein the parisons within a blow molder are supplied to various different processing stations (DE-OS 43 40 291). Typically, a blow molder includes a heating unit for tempering or pre-heating (thermal conditioning) of the parisons, as well as a blower device having at least one blowing station, in the area of which the respective parison that has previously been tempered is expanded into a container biaxially or multiaxially. The expansion is effected with the aid of a compressed gas (compressed air) as a pressure medium, which is introduced into the parison to be expanded using cavity pressure. The procedural course during such an expansion of the parison is explained in DE-OS 43 40 291.
The fundamental construction of a blowing station is described in DE-OS 42 12 583. Options for tempering the parisons are explained in DE-OS 23 52 926.
According to a typical processing operation, the containers produced by blow molding are fed into a subsequent filling unit, and filled there with the envisaged product or filling substance. Thus a separate blow molder and a separate filling unit are used. In that respect, it is also known that the separate blow molder and the separate filling machine are combined to form a machine module, i.e. an integral blow filling device, wherein moreover the blow molding and filling up are carried out at separate machinery components and successively.
It has, furthermore, already been proposed to manufacture containers, in particular also in the form of bottles made of thermally conditioned or pre-heated parisons, and, in that respect, simultaneously fill them with a liquid filling substance, which is introduced as a hydraulic pressure medium for expanding the parison or shaping the container with cavity and filling pressure, so that, simultaneously with the filling, the respective parison is deformed in to the container. Such methods, in the case of which simultaneous shaping and filling of the respective container occurs, can also be termed “hydraulic molding procedures” or “hydraulic container molding”.
When shaping the container from the parisons through the filling substance itself, i.e. using the filling substance as a hydraulic pressure medium, the only other thing required for shaping and filling the containers is a machine that does, however, have an increased complexity. Initial test results with such devices show, however, that the quality of the containers produced is still clearly below the quality of blow-molded containers produced in a conventional way. The cause of the latter is, among other things, that a large number of process parameters, which are available when carrying out the usual blow molding, either do not exist in the case of hydraulic container molding or have not yet been able to be developed.
With hydraulic container molding, a particular problem also consists in the fact that any pollution of the respective shaping and filling station or of the mound forming such a station, which is designed in a similar way to a blow mold of a blow molding machine for manufacturing containers from thermally conditioned parisons through blow forming with a compressed gas, needs to be avoided. In particular in the case of full or partial carbonation of the filling substance, there is a particular degree of risk of the respective shaping and filling station being polluted through losses of filling substance, in particular when lowering the internal pressure of the container, i.e. when relieving the container of the extremely high cavity and filling pressure on the ambient pressure. Such losses of filling substance are in particular caused by a massive amount of foam being generated when relieving the pressure, so that the simultaneous shaping and filling of containers using parisons and using the filling substance as a pressure medium (hydraulic molding technology), in particular for products containing CO2, could to date not be used.